1. Field of the Invention
The invention relates to the handling and curing of tobacco. More particularly, the invention relates to an efficient tobacco handling and curing system adaptable for use with existing tobacco trailers and slides and requiring only one handling of the tobacco leaves through the curing stage.
2. Description of the Prior Art
It has been the practice for laborers to travel between the rows of tobacco, hand prime tobacco leaves and transfer such leaves to the barn site on a trailer or slide. The leaves are then secured to tobacco sticks for curing on the tier poles provided in stick-type tobacco barns. This method of tobacco harvesting and curing requires that the leaves be handled repeatedly and in small quantities.
Bulk curing of tobacco on "racks" as generally described in U.S. Pat. No. 3,105,713 has become increasingly popular in recent years as a means of eliminating the cumbersome stringing operation involved in the conventional method. Bulk curing systems require that the tobacco be cured in closely packed bundles. Thus, it is extremely important that large amounts of warm air be forced through the tobacco leaves and that means be provided to carry away the moisture. The bulk curing systems of the prior art have the principal disadvantage of occasional uneven drying and curing due to an insufficient flow of air through the curing leaves.
The most recent known development in the curing of tobacco is the use of large curing boxes which are filled with green tobacco leaves in the field. The leaves are compressed and held securely within the curing boxes by "spikes" or "pins" which extend through the boxes and pierce the leaves. The boxes are then loaded into the tobacco barn for curing by forcing hot air through openings in the boxes. The known curing processes utilizing the curing box approach are the system described in U.S. Pat. No. 3,834,137 to Long Manufacturing Company of Tarboro, N.C., and the "Thermal" handling and curing system manufactured by Carolina Thermal Company of Charlotte, N.C.
The bulk curing barns of the prior art utilize both the down-flow and up-flow techniques for circulating the heated air. No system known to the applicants provides a uniform static pressure between the blower and the leaves in order to assure a uniform flow of hot air throughout the barn. A typical down-flow system for bulk curing tobacco on conventional racks is the "BULKTOBAC" system designed by Gas-Fired Products, Inc., of Charlotte, N.C.
A study of the prior art indicates that there is an acute need for a bulk tobacco curing system enabling the tobacco farmer to cure large quantities of closely packed tobacco in a tobacco barn having an even drying temperature throughout and sufficient air flow to dry all the leaves evenly.